What effect does the blow-up ratio have on film quality?

When many novices use the film blowing machine, they do not know how big the mold is, how wide the film can be blown, and even the transverse tension of the film made, and a longitudinal tension are particularly long. The resulting bag is not sealed securely.

This issue will give you a look at an important indicator of the film blowing machine, that is, the blowing ratio.

1.What is the blown film machine?

The blowing ratio is the smallest diameter of the bubble, which is the smallest diameter of the circle divided by the diameter of the die of the mold is very small, the diameter of the die of the mold.

2. What is the diameter of the bubble membrane?

The diameter of the vesicle is the diameter of the circle. The width of the product that we make when we flatten the film is the diameter multiplied by π, which is 3.14 divided by 2. 

3. The correct blowing ratio directly affects the tearing strength of the film, as well as its tensile strength.

High pressure LDPE is also low density polyethylene, and its blowing ratio is between 2 and 3, that is, the die diameter is 200 mm, 20 cm. The width of the film is 600 mm, 60 cm. 

Low pressure HDPE is high density polyethylene blowing ratio of 4 to 6. If the diameter of the die is 50 mm 5 cm, the maximum width of the film is 500 mm. 

PPE, that is, polypropylene blowing ratio is between 1.1 and 2, if the diameter of the die is 300 mm, 30 cm, the widest width of the film can reach 600.

Let's take blowing low pressure material as an example, I share a table for you. In addition to achieving an effective blowing ratio, it is also necessary to pay attention to controlling the height of the condensing line, that is, the height of the double line, to ensure that the film bubble meets the production process requirements on the basis of stability. Otherwise, the film products made to tear strength will be very poor, a pull will break.